Pitman



UNITED STATES PATENT OFFICE.

JOHN A. MCANULTY, OF MINNEAPOLJS, MINNESOTA.

PITMAN.

SPECIFICATION forming part of Letters Patent No. 394:,281, dated December 11, 1888.

Application filed March 26, 1888. $erial No. 268,548. (No model.)

as will enable others skilled in the artto which it appertains to make and use the same.

M y invention relates to pitmen for connecting cranks or eccentrics, either revolving or rocking, to parts of macl'rinery which are de signed to be reciprocated; and it consists in the improved construction and arrangement or combination of parts of the pitman and its connections, which will be hereinafter fully disclosed in the description, drawings, and claims.

The objects of my invention are, tirst, to provide improved means for vibrating or reciprocating parts of macl'linery without the use of separate springs for supporting the same, and, second, to provide in'lproved means for attaching pitmen to eccentrics, eccentricshafts, or crank-pins in such a manner that rattling and heating of boxes will be pre vented and free play allowed to the part vibrated or reciprocated without binding or 1111' equal wear upon said eccentrics, eccentricshafts, or crank-pins.

In the accompanying drawings, forming part of this specification, wherein the same reference-numerals indicate the same or corresponding parts, ,l igure 1 represents a top plan view of my improved pitman connected to an eccentric-shaft and to a part of a machine adapted to be vibrated or reciprocated, and Fig. 2 a longitrulinal section of the same 011 line a: .1: of Fig. 1.

111 the drawings, the numeral 1 indicates the shaft, which is provided with a crank or an eccentric and a pitman attached thereto, only one of each being herein disclosed; but in practice two or more may be employed, as their construction will be the same.

2 represents the eccentric, which may be formed by reducing the shaft, as shown in the drawings, or by attaching an eccentric of larger radius than the shaft, or in any of the well-known ways of forming cranks or eccentries.

The cylindrical box 3, as shown in section in Fig. 2, is formed in two parts and so fitted upon the eccentric as to permit the latter to move or revolve freely within it; also, the upper part thereof may be provided with an oil-cup, 4, adapted to receive and distribute a suitable lubricant to the eccentric and throughout the interior of the box. The two parts of the box have diametrically-opposite conical depressions 5 placed at an angle of about forty-five degrees to the axial line of the pitman and the plane of the mechanism to be reciprocated.

(3 represents the pitman, which is formed at its inner end with a curved head, 7, which passes around more than half of the box, preferably beneath the same. A point or pivot, S, is formed upon the inner side of this curved head and so titted into the depression 5 in the lower part of the box as to pivot freely therein laterally; also, the extreme end of this curved head is formed with a screwthreaded opening, 9, at a point diametrically opposite thepoint or pivot S. A set-screw, 9, which also acts as a pivot, passes through this opening and fits with its conical end in the depression 5 in the upper part of the box. A binding-nut, 10, firmly holds the set-screw in its adjusted position. By tightening this setscrew a perfect adjustment of the two-part box to its crank or eccentric is effected and wear compensated for.

The outer end of the pitman or connectingrod ti, which is attached to the part to be vibrated or rcciprocated, is formed with a spiral or coiled spring, '11, which, being lengthwise compressible and expansible and laterally and vertically yielding or movable, serves to permit the part to which it is attached to move freely in all directions, and also serves to cushion the shock ordinarily incident to the reciprocating or vibrating frames employed in various kinds of machinessuch as middlings-purifiers, feed-regulators, and graincleanerses )ecially in those machines in which the parts moved are rapidly reciprocated. This cushioning or avoidance of jar is due to the resiliency of the metal forming the spring portion of the pitmen, which enables me to dispense with the springs ordinarily employed for supporting shaking frames in machines of the kind just named.

It will be obvious from the foregoing that the spring portion of the pitman in connection with the pivots, arranged at an angle to its axial line and forming a laterally-mova- 5 ble connection between the inner end of the same and the eccentric, will permit freedom of lateral movement of said pitman at both ends, and also allow the part being reciprocated to deviate from a line at right angles to the shaft; that all irregularities in the motion of said reciprocating or vibrating part will be taken up or compensated for; that uneven wear upon the eccentric and the two-part boxing due to heating from the binding or cramping-and rapid movements of the parts, is entirely avoided, and, also, that rattling of the joints or couplings is prevented.

This construction of pitman is especially adapted to be used in machines of the char- 2o actcr above referred to for the treatment of grain or its products in any form, since in that class of machines the principal parts not only require reciprocatin or vib rating movement, but cushioning, as they are subjected to varying loads or pressures of stock; but, as is evident, my generallyimproved pitman, with its curved head pivoted to the crankpin or eccentric at diametrically-opposite points, may be employed in any mechanism in which a pitman is required to permit of lateral or vertical play of the part to which it is attached.

I do not broadly claim a piti-nan having a coiled or spiral spring near its outer end, but

3 5 only in combination or arrangement withihe other parts and features herein specified in the claims; also, I do not claim the combination of a crank-pin and a pitman connected thereto by means of a ring and a box within said ring, which is pivoted upon two points which are coincident with the axis of said pitman, as this construction does not permit of the wide range and freedom of lateral movement of the outer end of the pitman that is incident to the laterally-movable pitman employed by me and provided with pivots arranged at an angle to the axial line of said pitman; also, I do not herein broadly claim this construction of laterally-movable pitman, as the same forms part of a similar in vention for which I have filed application for Letters Patent simultaneously herewith, Serial No. 208,547.

Having thus fully described the construction, arrangement, and operation of the several parts of my invention and also the advantages thereof, what I claim as new is 1. The combination of an eccentric, a box mounted thereon, and a laterally movable pitman provided with pivots at its inner end arranged at an angle to its axial line, and provided near itsouter end with a spring portion which is lengthwise compressible and expansible and laterally and vertically yielding or movable, substantially as and for the purpose described.

2. The combination of an eccentric, a box mounted thereon, and a laterall y-movable pitman provided with pivots at its inner end, arranged at an angle to its axial line, and provided nearits outer end with a coiled or spiral spring, substantially as and for the purpose described.

3. The combination, with a pitman formed with a curved head having diametrically-opposite pivotal points at its end and inner side, and with a coiled or spiral spring near its outer end, of an eccentric and a box mounted thereon and formed with diametriCally-opposite depressions, in which said pivotal points rest, substantially as described.

4. The combination of a shaft provided with an eccentric, and a cylindrical box mounted thereon and provided with diametrically-opposite depressions in its sides, with a pitman having a spiral spring near its outer end and a curved head at its inner end, formed with a pivotal point on its inner side resting in one of said depressions, with a screw threaded opening in its outer end and. provided with a pointed set-screw having its end resting in the other depression, and a clamping-nut for holding said screw, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN A. MCANULTY.

lVitnesses:

A. H. MoANUL'rY, A. C. PAUL. 

